1. Field of the Invention
The present invention relates to an optical sight, more particularly to an optical sight having a range-finding function.
2. Description of the Related Art
As shown in FIGS. 1, 2, and 3, a conventional optical laser sight having a range-finding function includes an outer barrel unit 1, an objective lens unit 2, an ocular lens unit 3, a magnification unit 4 disposed in the outer barrel unit 1 and which can adjust a magnification of the optical laser sight, two adjusting devices 5, 6 respectively disposed on a right side and atop side of the outer barrel unit 1, and a range-finding module 7 associated with the magnification unit 4. The outer barrel unit 1 includes a barrel body 101 with a rectangular opening 107, a main circuit board 102 mounted in the rectangular opening 107 and located on a left side of the magnification unit 4, a cover body 103 mounted on a left side of the barrel body 101, a waterproof ring 104 positioned between the cover body 103 and the barrel body 101, an operating button 105 mounted on the cover body 103, and an outer cover 106 mounted on the barrel body 101 and covering the cover body 103.
The magnification unit 4 includes an inner barrel component 401.
The adjusting devices 5, 6 respectively include adjustment screws 501, 601, which abut against a right side and a top side of the inner barrel component 401, respectively.
The range-finding module 7 includes a light emitter 701 disposed on the right side of the inner barrel component 401 and electrically connected to the main circuit board 102, a light receiver 702 disposed on the top side of the inner barrel component 401 and electrically connected to the main circuit board 102, a first prism 703 disposed on a front end of the inner barrel component 401, and a second prism 704 disposed in the inner barrel component 401.
The light emitter 701 emits light that is directed to a target through reflection by the first prism 703. The light then reflected by the target passes again through the first prism 703, and is reflected by the second prism 704 to reach the light receiver 702. Accordingly, the main circuit board 102 can calculate a distance to the target.
However, this conventional optical sight has disadvantages as follows:
i) As shown in FIG. 1, the main circuit board 102 needs to be mounted on the left side of the magnification unit 4 due to the arrangement of internal circuitry and wiring, and hence, the large rectangular opening 107 must be formed in the barrel body 101 to allow such mounting of the main circuit board 102. However, this makes it necessary for the optical sight to include a waterproofing mechanism for the main circuit board 102, thereby resulting in a complicated structure and increased manufacturing costs. In addition, the main circuit board 102 is located on the left side of the barrel body 101, which places significant limitations on design due to the waterproofing required for the main circuit board 102.
ii) As shown in FIGS. 2 to 4, it is necessary to dispose the light emitter 701 and the light receiver 702 respectively to the right side and the top side of the inner barrel component 401 due to the positioning of the main circuit board 102. Furthermore, the adjusting devices 5, 6 are also disposed respectively on the right side and the topside of the barrel body 101 of the outer barrel unit 1. As a result, the light emitter 701 and the light receiver 702 must be arranged out of the way of the adjusting devices 5, 6 (e.g., respectively to the front of the adjusting devices 5, 6). Ultimately, limitations are placed with respect to the degree to which the mounting positions of the adjusting devices 5, 6 may be varied.